One area of alternative fuels that has gained a lot of interest over the last year or two is algae biodiesel. This is probably because it will produce 10-30 times what the best oil producing crops in America will produce. Here are some of the gallon per acre figures in this chart (note that the gpa figure varies greatly depending on who you ask, where it is grown, how it is planted, the strain used, how many harvests per year, etc).... Oil Crop Gallons of Oil per Acre Soybeans 48, Rapeseed 127, Jatropha 435-2000, Algae 5000-15,000 Algae consumes carbon dioxide, thus reducing harmful greenhouse gases. Most algae farms are being built right next to coal fired electricity plants so they have a steady supply of CO2. I don't know much about it, but those "carbon credits" are very valuable. Total estimated carbon credit trading this year is about $72 billion dollars. And is expected to reach $32 Trillion by 2020. The byproduct left over after extracting the oil can be used in cattle feed, vitamins, pigments, cosmetics, etc. Algae Biodiesel